1. Field of the Invention
The present invention relates to a sliding door structure for a vehicle with a side panel such as a cab side for covering the side of a vehicle body and a roof connected to the side panel for covering the top of the vehicle body.
2. Description of Related Art
One of prior art door structures for a vehicle of a type that is provided with a side panel such as a cab side for covering the side of a vehicle body and a roof connected to the side panel for covering the top of the vehicle body is disclosed in, for example, Unexamined Japanese Patent Publication No. 04 (1992)-339017. This type of vehicle, e.g. a one-box car, has a side door opening formed as an access opening to a rear sheet in the side panel and a side door slidably mounted on one side of a vehicle body for movement between a closed position in the side door opening and an open position wherein the side door extends along the outer surface of the side panel to fully expose the access opening. The vehicle body is provided with overhead, middle or center and lower guide rails. The side door is slidably connected to the guide trucks so as to travel between the closed position and the open position in a lengthwise direction of the vehicle body.
This type of one-box car has a center guide rail installed to an outer side body panel and, inconsequence, the one-box car often looks unattractive in outer appearance. On the other hand, the one-box car, that has a comparatively high vehicle height, has no particular problem with facility and convenience of getting on and off the car. However, sporty vehicles, that are generally made low in vehicle height in light of design requirements, have a problem with facility and convenience of getting on and off the car in such the case where a sliding door opens and closes an access opening defined within a side body panel only. In particular, in the case where the sporty car is equipped with a sliding door slidably mounted to the car body through overhead, center and lower guide rails, the overhead guide rail constitutes a limiting factor of good facility and convenience of getting on and off the car.
A combination of such a sliding door and a roof door such as disclosed in Unexamined Japanese Patent Publication No. 05 (1993)-339017 is one of solutions to the problem of facility and convenience of getting on and off. However, the combination door imposes on a passenger the troublesome operation that the passenger has to operate both sliding door and roof door independently when getting on and off the car. This door operation resists good facility and convenience of getting on and off the car. In light of these problems, it appears suitable for eliminating the problem to provide a car with a door opening extending from a side body to a roof and a single sliding door having a side door portion in conformity in configuration with a side opening portion and a roof door portion in conformity in configuration with a roof opening portion. In this instance, the sliding door structure deeds a mechanism for moving the sliding door rearward in a lengthwise direction of the car after drawing the roof door portion laterally away from the roof opening in order to open the door opening. This mechanism and door operation leads to a large distance of lateral movement of the sliding door.
It is therefore an object of the present invention to provide a door structure for a vehicle with a door opening extending from a side door panel to a roof in which a sliding door having a side door portion and a roof door portion.